Method for preparing flame-retardant bamboo shaving board through soybean oil-based adhesive

Abstract

The invention provides a method for preparing a flame-retardant bamboo shaving board by using a soybean oil-based adhesive, which comprises the following steps: adding 1, 3-butanediol dimethacrylate, epoxidized soybean oil acrylate, isocyano ethyl methacrylate and an initiator into a single-mouth flask according to a mass ratio, mechanically stirring at room temperature, and uniformly mixing to prepare the soybean oil-based adhesive. And uniformly mixing the obtained adhesive with dried bamboo shavings and a flame retardant, and carrying out hot press molding to prepare the flame-retardant bamboo shaving board. According to the prepared flame-retardant bamboo shaving board, raw material sources are environmentally friendly, the adhesive does not contain formaldehyde, and the flame-retardant bamboo shaving board has good static bending intensity, internal bonding strength, water resistance and flame retardance.

Description

Technical Field

[0001] The invention relates to the technical field of biomass composite materials, in particular to a method for preparing a flame-retardant bamboo particle board using a soybean oil-based adhesive. Background Art

[0002] Traditional industrial adhesives, such as phenolic resins and urea-formaldehyde resins, are widely used in many fields such as construction, automobiles, textiles and medical treatments due to their excellent bonding properties, ease of use and economic benefits. However, the production process of these adhesives relies on non-renewable resources such as petroleum, which has aggravated the global energy shortage problem and caused serious pollution to the environment.

[0003] In order to meet the needs of sustainable industrial development, the adhesive industry is transforming towards a rational industrial structure, focusing on the research and development of renewable, environmentally friendly new formaldehyde-free adhesives. In this transformation process, biomass resources such as soybean oil and polysaccharides are regarded as ideal raw materials for manufacturing polymers due to their renewable properties. In particular, natural soybean oil, thanks to its unique triglyceride structure and rich functional groups, has become an important raw material for the development of composite resin matrices.

[0004] In the wood processing industry, low production efficiency and low comprehensive resource utilization are common problems. China has abundant bamboo forest resources. A large number of by-products such as bamboo shavings and bamboo chips are produced during the bamboo processing process, which are often consumed as fuel. Bamboo shavings are mainly composed of cellulose, hemicellulose, lignin and water extracts. Their surface is rich in free hydroxyl groups and is an ideal raw material for making bamboo particleboard. Bamboo particleboard is a man-made board formed by hot pressing of raw materials such as small-diameter bamboo, bamboo stem tips and bamboo product residues. It provides the possibility of efficient use of residual materials, which is of great significance for resource conservation and environmental protection. With the improvement of people's living standards, the requirements for flame retardancy and environmental protection of furniture boards are also constantly increasing. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive.

[0006] To achieve the above objectives, the present invention adopts the following technical scheme: a method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive, wherein the flame retardant bamboo particleboard is prepared by cold-pressing a soybean oil-based adhesive, bamboo shavings and a flame retardant, and then hot-pressing the resulting assembly.

[0007] Preferably, the soybean oil-based adhesive is obtained by adding 1,3-butylene glycol dimethacrylate, epoxy soybean oil acrylate, isocyanoethyl methacrylate and an initiator into a single-necked flask according to a mass ratio, and mixing them uniformly after mechanical stirring at room temperature, wherein the initiator is benzoyl peroxide.

[0008] Preferably, the raw material components of the flame retardant bamboo particle board are as follows by weight: 16-18 parts of soybean oil-based adhesive, 73-82 parts of bamboo shavings and 5-15 parts of flame retardant, wherein the flame retardant is ammonium polyphosphate.

[0009] Preferably, the raw material components of the soybean oil-based adhesive are as follows by mass: 56-70 parts of 1,3-butylene glycol dimethacrylate, 24-30 parts of epoxy soybean oil acrylate, 4-12 parts of isocyanoethyl methacrylate and 1-5 parts of initiator benzoyl peroxide.

[0010] A specific method for preparing a flame-retardant bamboo particleboard using a soybean oil-based adhesive is as follows: 1, 3-butylene glycol dimethacrylate, epoxy soybean oil acrylate, isocyanoethyl methacrylate and benzoyl peroxide are added into a single-necked flask according to a mass ratio, and the mixture is mechanically stirred at room temperature for 5-20 min and then uniformly mixed to obtain a soybean oil-based adhesive; bamboo shavings are dried and uniformly mixed with the soybean oil-based adhesive by mechanical stirring; the shavings after adhesive application are laid into a mold, the density is set to 0.5-0.8 kg / m3, the thickness is 5-10 mm, cold pressing is performed at room temperature and 5-20 MPa, and then hot pressing is performed; the hot pressing temperature is 130-150°C, the pressure is 15-25 MPa, and the hot pressing time is 5-20 min; after the hot pressing is completed, a flame-retardant bamboo particleboard is obtained.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The soybean oil-based adhesive prepared by the present invention is a type of environmentally friendly thermosetting resin adhesive with high bio-based content and no formaldehyde; the adhesive has good mechanical properties and stability. At the same time, the use of low-priced, green and harmless soybean oil as a raw material provides a new idea for the production and application of soybean oil.

[0012] The present invention adopts an optimized process parameter combination, the dosage ratio (mass ratio) of 1,3-butylene glycol dimethacrylate to epoxy soybean oil acrylate is 7:3, the dosage ratio of the uniformly mixed copolymer to isocyanoethyl methacrylate is 9:1, and the dosage of the initiator is 2 wt%, so as to prepare a soybean oil-based thermosetting resin adhesive with excellent mechanical properties and high temperature resistance.

[0013] The present invention adopts an optimized hot pressing process, applies the soybean oil-based adhesive according to 18 wt% of the absolute dry weight of the bamboo shavings, adds a flame retardant according to 0-15 wt% of the absolute dry weight of the bamboo shavings, the hot pressing temperature is 140°C, and the pressure is controlled to be 22 MPa, so as to prepare a formaldehyde-free flame-retardant bamboo particleboard with excellent mechanical properties and flame retardancy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a vertical burning diagram of soybean oil based flame retardant bamboo particleboard.

[0015] Figure 2 These are the mechanical properties data of soybean oil-based flame retardant particleboard.

[0016] Figure 3 It is the limiting oxygen index of soybean oil-based flame retardant particleboard.

[0017] Figure 4 It is the vertical burning test result of soybean oil-based flame retardant particleboard.

[0018] in, BP-0 means flame retardant bamboo particleboard without added ammonium polyphosphate; BP-5 represents a flame-retardant bamboo particleboard with 5 wt% ammonium polyphosphate added; BP-10 represents a flame-retardant bamboo particleboard with 10 wt% ammonium polyphosphate added; BP-15 represents a flame retardant bamboo particleboard with 15 wt% ammonium polyphosphate added. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application, as follows.

[0020] Raw materials: Epoxidized soybean oil acrylate was purchased from Jiangsu Litian Technology Co., Ltd.; 1, 3-butylene glycol dimethacrylate and isocyanatoethyl methacrylate were purchased from Shanghai Jingchun (Aladdin) Industrial Co., Ltd.; ammonium perphosphate and benzoyl peroxide were purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; bamboo shavings were provided by Furen Group Forest Industry Co., Ltd. (Nanping, Fujian).

[0021] Example 1 Formaldehyde-free bamboo particleboard The preparation process of soybean oil-based adhesive is as follows: 22.3 g of 1, 3-butylene glycol dimethacrylate, 9.5 g of epoxy soybean oil acrylate, 3.55 g of isocyanoethyl methacrylate and 0.71 g of initiator are mixed evenly to obtain soybean oil-based thermosetting resin adhesive. Soybean oil is a renewable resource. Compared with traditional petroleum-based raw materials, it is more in line with the requirements of sustainable development, can reduce dependence on fossil fuels and reduce carbon emissions; 1,3-butylene glycol diacrylate provides good flexibility and adhesion, which can improve the mechanical properties of the adhesive; epoxy soybean oil acrylate increases the heat resistance and chemical resistance of the adhesive, while increasing its curing speed; isocyanoethyl acrylate enhances the crosslinking density of the adhesive, thereby improving its strength and durability; using benzoyl peroxide as an initiator can promote polymerization and accelerate the curing process of the adhesive.

[0022] At room temperature, 161.5 g of dried bamboo shavings were mechanically stirred and mixed with adhesive. Bamboo, as a renewable resource, has high strength and toughness. Soybean oil-based thermosetting resin adhesive was applied at 18% of the absolute dry weight of bamboo shavings, and the shavings after adhesive application were laid into the mold. The density was set to 0.75 kg / m3 and the thickness was 7 mm. By precisely controlling the mass ratio of bamboo shavings to adhesive, the structure of the bamboo particleboard can be ensured to be uniform, which helps to improve the strength and stability of the board. Cold pressing was carried out at room temperature and 10 MPa. The physical properties of the material are relatively stable at room temperature, and no high-temperature heating is involved, and no harmful gases and pollutants will be generated. After hot pressing, the bamboo particle composite board was obtained. The hot pressing operation temperature was 140℃, the pressure was 20 MPa, and the hot pressing time was 10 min to ensure that the bamboo particle composite board was completely cured. Cold pressing of the slab can ensure the uniform distribution of the wood chips, partially solidify them, and enhance the stability of the slab. Hot pressing can improve the bending strength, compressive strength and impact resistance of the board through high temperature and high pressure.

[0023] In the preparation process, the soybean oil-based adhesive is 18 wt% of the mass of the bamboo shavings.

[0024] Example 2 Flame retardant formaldehyde-free bamboo particleboard The preparation process of soybean oil-based adhesive is as follows: 22.3 g of 1, 3-butylene glycol dimethacrylate, 9.5 g of epoxy soybean oil acrylate, 3.55 g of isocyanoethyl methacrylate and 0.71 g of initiator are mixed evenly to obtain soybean oil-based thermosetting resin adhesive. Soybean oil is a renewable resource. Compared with traditional petroleum-based raw materials, it is more in line with the requirements of sustainable development, can reduce dependence on fossil fuels and reduce carbon emissions; 1,3-butylene glycol diacrylate provides good flexibility and adhesion, which can improve the mechanical properties of the adhesive; epoxy soybean oil acrylate increases the heat resistance and chemical resistance of the adhesive, while increasing its curing speed; isocyanoethyl acrylate enhances the crosslinking density of the adhesive, thereby improving its strength and durability; using benzoyl peroxide as an initiator can promote polymerization and accelerate the curing process of the adhesive.

[0025] At room temperature, 161.5 g of dried bamboo shavings and 8.1 g of ammonium polyphosphate were mixed evenly by mechanical stirring. Bamboo, as a renewable resource, has high strength and toughness. As a flame retardant, ammonium polyphosphate will decompose to produce non-combustible gas when heated, and form an expanded carbon layer, which can isolate oxygen and reduce heat transfer, thereby effectively preventing the spread of flames. At the same time, it will not produce toxic gases when burned and is easy to degrade. Further, it can also improve the impact resistance and tensile strength of the board. Then, soybean oil-based thermosetting resin adhesive was applied at 18% of the absolute dry weight of bamboo shavings, and the shavings after adhesive application were laid into a mold. The density was set to 0.75 kg / m3 and the thickness was 7 mm. Cold pressing was performed at room temperature and 10 MPa. The physical properties of the material were relatively stable at room temperature, and no harmful gases and pollutants were generated without high-temperature heating. After hot pressing, the bamboo shavings composite board was obtained. The temperature of the hot pressing operation was 140°C, the pressure was 20 MPa, and the hot pressing time was 10 min to ensure that the bamboo shavings composite board is fully solidified. Cold pressing of the shavings can ensure the uniform distribution of the shavings, partially solidify them, and enhance the stability of the slab. Hot pressing can improve the bending strength, compressive strength and impact resistance of the board through high temperature and high pressure.

[0026] In the preparation process, the amount of ammonium polyphosphate used is 5 wt% of the wood chips, and the amount of soybean oil-based adhesive is 18 wt% of the wood chips.

[0027] Example 3 Flame retardant formaldehyde-free bamboo particleboard The preparation process of the soybean oil-based adhesive is as follows: 22.3 g of 1, 3-butylene glycol dimethacrylate, 9.5 g of epoxy soybean oil acrylate, 3.55 g of isocyanoethyl methacrylate and 0.71 g of initiator are mixed evenly to obtain a soybean oil-based thermosetting resin adhesive.

[0028] At room temperature, 161.5 g of dried bamboo shavings and 16.2 g of ammonium polyphosphate were mixed evenly by mechanical stirring, and then soybean oil-based thermosetting resin adhesive was applied at 18% of the absolute dry weight of the bamboo shavings. The shavings after adhesive application were laid into a mold with a density set to 0.75 kg / m3 and a thickness of 7 mm. The embryos were cold pressed at room temperature and 10 MPa, and then hot pressed to obtain the bamboo shavings composite board. The hot pressing operation temperature was 140℃, the pressure was 20 MPa, and the hot pressing time was 10 min.

[0029] In the preparation process, the amount of ammonium polyphosphate used is 10 wt% of the wood chips, and the amount of soybean oil-based adhesive is 18 wt% of the wood chips.

[0030] Example 4 Flame retardant formaldehyde-free bamboo particleboard The preparation process of the soybean oil-based adhesive is as follows: 22.3 g of 1, 3-butylene glycol dimethacrylate, 9.5 g of epoxy soybean oil acrylate, 3.55 g of isocyanoethyl methacrylate and 0.71 g of initiator are mixed evenly to obtain a soybean oil-based thermosetting resin adhesive.

[0031] At room temperature, 161.5 g of bamboo shavings and 24.2 g of high ammonium phosphate were mixed evenly by mechanical stirring, and then soybean oil-based thermosetting resin adhesive was applied at 22% of the absolute dry weight of the bamboo shavings. The shavings after adhesive application were laid into a mold with a density set to 0.75 kg / m3 and a thickness of 7 mm. The embryos were cold pressed at room temperature and 10 MPa, and then hot pressed to obtain the bamboo shavings composite board. The hot pressing operation temperature was 140°C, the pressure was 20 MPa, and the hot pressing time was 30 min.

[0032] In the preparation process, the amount of ammonium polyphosphate used is 15 wt% of the wood chips, and the amount of soybean oil-based adhesive is 18 wt% of the wood chips.

[0033] Mechanical properties test of formaldehyde-free bamboo particleboard: The mechanical properties test method of particleboard refers to the requirements specified in GB / T17657-2013. The particleboard is cut into rectangular specimens (length 170 mm, width 50 mm, thickness 6 mm) to test the static bending strength of particleboard; the mechanical properties test is completed on a microcomputer-controlled electronic universal testing machine.

[0034] The elastic modulus is calculated as:

[0035] Where l1 is the distance between supports, b is the width of the specimen, and t is the thickness of the specimen. F 2- F 1 is 0.3 times of the maximum load, and a2 and a1 are the deformations of the specimens in the F2 and F1 intervals.

[0036] Test of internal bonding strength: Cut the bamboo particle board into a 50 mm × 50 mm square specimen and place it in an environment of 20°C and 65% humidity until it reaches a constant mass; apply hot melt adhesive to one side of the metal clamp to adhere the sample, wait for the sample to cool and fix, and glue another metal clamp to the other side of the sample; put the prepared specimen into a universal mechanical testing machine and load it at a constant rate of 2 mm / min until the specimen is destroyed; record the value of the internal bonding strength of each group of specimens, and take the arithmetic mean of the results of the same component.

[0037] Flame retardant performance test of formaldehyde-free bamboo particleboard: The limiting oxygen index (LOI) of the resin was tested on the British FTT 0077 limiting oxygen index instrument according to the ASTM D 2863-97 standard, and a rectangular specimen (specification: 100 mm long, 12.5 mm wide, and 7 mm thick) was used for the test. The vertical combustion performance of the sample was tested on the British FTT 0082 vertical combustion tester according to the UL-94 method, and a rectangular specimen (specification: 125 mm long, 10 mm wide, and 7 mm thick) was used for the test. The cone calorimetry test was carried out on the British FTT0242 horizontal vertical combustion tester according to the ASTM E1354 standard, with a heat flux of 35 kW / m2, and a rectangular specimen (specification: 100 mm long, 100 mm wide, and 7 mm thick) was used for the test.

[0038] Depend on Figure 2 It can be seen that the static bending strength of soybean oil-based flame retardant bamboo particleboards BP-0, BP-5, BP-10 and BP-15 are 24 MPa, 26 MPa, 28 MPa and 29 MPa, respectively. The elastic modulus of soybean oil-based flame retardant bamboo particleboards BP-0, BP-5, BP-10 and BP-15 are 3245 MPa, 3657 MPa, 4071 MPa and 4426 MPa, respectively. The internal bonding strength of soybean oil-based flame retardant bamboo particleboards BP-0, BP-5, BP-10 and BP-15 are 2.01 MPa, 2.05 MPa, 2.00 MPa and 1.90 MPa, respectively. It can be seen from the data in the table that with the increase in the amount of ammonium polyphosphate added, the particleboard can withstand a greater bending load and is more difficult to deform when under stress; further, the greater the pressure, the more stable the internal bonding strength of the particleboard, indicating that the particleboard can resist delamination well when under stress and will not be affected by external forces to destroy its internal stability, and has good static bending strength and internal bonding strength.

[0039] Depend on Figure 3 It can be seen that the limiting oxygen index of soybean oil-based flame-retardant bamboo particleboard BP-0, BP-5, BP-10 and BP-15 are 22.19%, 25.40%, 26.45% and 35.9% respectively. With the increase of ammonium polyphosphate, the limiting oxygen index limit of particleboard increases; when the amount of ammonium polyphosphate is 15%, the particleboard meets the flame retardant standard, that is, the limiting oxygen index is greater than or equal to 27%. It can be seen that with the increase of ammonium polyphosphate, particleboard is not easy to burn or burns slowly when encountering a fire source, has good flame retardant properties, and will not easily deform, ensuring the stability and integrity of the structure.

[0040] Depend on Figure 1 and Figure 4It can be seen that the vertical burning grades (GB / T 2408-2008) of soybean oil-based flame-retardant bamboo particleboards BP-0, BP-5, BP-10 and BP-15 are V-2, V-2, V-0 and V-0 respectively. With the increase of ammonium polyphosphate, the vertical burning grade increases accordingly; when the amount of ammonium polyphosphate added is 10%, the vertical burning grade of the particleboard has reached V-0. It can be seen that with the increase of ammonium polyphosphate, the particleboard is not easy to burn or burns slowly when encountering a fire source, has good flame retardant properties, and will not easily deform, ensuring the stability and integrity of the structure.

[0041] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive, characterized in that: The flame retardant bamboo particle board is prepared by cold pressing a soybean oil-based adhesive, bamboo particles and a flame retardant, and then hot pressing the cold pressed embryos.

2. The method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive as claimed in claim 1, characterized in that The soybean oil-based adhesive is prepared by the following method: 1,3-butylene glycol dimethacrylate, epoxy soybean oil acrylate, isocyanoethyl methacrylate and an initiator are added into a single-necked flask according to a mass ratio, and the mixture is mechanically stirred at room temperature and then uniformly mixed, wherein the initiator is benzoyl peroxide.

3. The method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive as claimed in claim 1, characterized in that: The raw material components of the flame retardant bamboo particle board are as follows: 16-18 parts of soybean oil-based adhesive, 73-82 parts of bamboo shavings and 5-15 parts of flame retardant, wherein the flame retardant is ammonium polyphosphate.

4. The method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive as claimed in claim 1, characterized in that: The raw material components of the soybean oil-based adhesive are as follows by weight: 56-70 parts of 1,3-butylene glycol dimethacrylate, 24-30 parts of epoxy soybean oil acrylate, 4-12 parts of isocyanoethyl methacrylate and 1-5 parts of initiator benzoyl peroxide.

5. The method for preparing a flame retardant bamboo particleboard using a soybean oil-based adhesive as claimed in claim 1, characterized in that: The specific preparation method is as follows: 1, 3-butylene glycol dimethacrylate, epoxy soybean oil acrylate, isocyanoethyl methacrylate and benzoyl peroxide are added into a single-necked flask according to the mass ratio, and the mixture is evenly mixed after mechanical stirring at room temperature for 5 to 20 minutes to obtain a soybean oil-based adhesive; the bamboo shavings are dried and evenly mixed with the soybean oil-based adhesive by mechanical stirring; the shavings after adhesive application are laid into a mold, the density is set to 0.5 to 0.8 kg / m3, the thickness is 5 to 10 mm, cold pressing is performed at room temperature and 5 to 20 MPa, and then hot pressing is performed; the hot pressing temperature is 130 to 150°C, the pressure is 15 to 25 MPa, and the hot pressing time is 5 to 20 minutes; after the hot pressing is completed, a flame-retardant bamboo particleboard is obtained.

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